SLUSBV4B June   2018  – September 2020 BQ40Z80

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Primary (1st Level) Safety Features
      2. 8.3.2  Secondary (2nd Level) Safety Features
      3. 8.3.3  Charge Control Features
      4. 8.3.4  Gas Gauging
      5. 8.3.5  Multifunction Pins
      6. 8.3.6  Configuration
        1. 8.3.6.1 Oscillator Function
        2. 8.3.6.2 System Present Operation
        3. 8.3.6.3 Emergency Shutdown
        4. 8.3.6.4 2-Series, 3-Series, 4-Series, 5-Series, or 6-Series Cell Configuration
        5. 8.3.6.5 Cell Balancing
      7. 8.3.7  Battery Parameter Measurements
        1. 8.3.7.1 Charge and Discharge Counting
      8. 8.3.8  Lifetime Data Logging Features
      9. 8.3.9  Authentication
      10. 8.3.10 LED Display
      11. 8.3.11 IATA Support
      12. 8.3.12 Voltage
      13. 8.3.13 Current
      14. 8.3.14 Temperature
      15. 8.3.15 Communications
        1. 8.3.15.1 SMBus On and Off State
        2. 8.3.15.2 SBS Commands
    4. 8.4 Device Functional Modes
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Using the BQ40Z80EVM with BQSTUDIO
        2. 9.2.2.2 High-Current Path
          1. 9.2.2.2.1 Protection FETs
          2. 9.2.2.2.2 Chemical Fuse
          3. 9.2.2.2.3 Lithium-Ion Cell Connections
          4. 9.2.2.2.4 Sense Resistor
          5. 9.2.2.2.5 ESD Mitigation
        3. 9.2.2.3 Gas Gauge Circuit
          1. 9.2.2.3.1 Coulomb-Counting Interface
          2. 9.2.2.3.2 Power Supply Decoupling and PBI
          3. 9.2.2.3.3 System Present
          4. 9.2.2.3.4 SMBus Communication
          5. 9.2.2.3.5 FUSE Circuitry
        4. 9.2.2.4 Secondary-Current Protection
          1. 9.2.2.4.1 Cell and Battery Inputs
          2. 9.2.2.4.2 External Cell Balancing
          3. 9.2.2.4.3 PACK and FET Control
          4. 9.2.2.4.4 Pre-Discharge Control
          5. 9.2.2.4.5 Temperature Output
          6. 9.2.2.4.6 LEDs
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Protector FET Bypass and Pack Terminal Bypass Capacitors
      2. 11.1.2 ESD Spark Gap
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.2.3.3 System Present

The System Present signal is used to inform the gas gauge whether the pack is installed into or removed from the system. In the host system, this pin is grounded. The PRES pin of the BQ40Z80 is used if J5[1, 2] jumper is installed, and is occasionally sampled to test for system present. To save power, an internal pullup is provided by the gas gauge during a brief 4-μs sampling pulse once per second. A resistor can be used to pull the signal low and the resistance must be 20 kΩ or lower to ensure that the test pulse is lower than the VIL limit. The pullup current source is typically 10 µA to 20 µA.

Because the System Present signal is part of the pack connector interface to the outside world, it must be protected from external electrostatic discharge events. An integrated ESD protection on the PRES device pin reduces the external protection requirement to just R12 for an 8-kV ESD contact rating. However, if it is possible that the System Present signal may short to PACK+, then an E2 spark gap must be included for high-voltage protection.